The objective of this paper works is to study, a stability analysis of two dimensional boundary layer forced convection over a fixed vertical plate vary in viscosity and prandtl number with time dependent . The governing equations are transformed to non linear coupled partial differential equations with boundary conditions have been solved numerically by finite difference scheme in combination with quasi-linearization technique with suitable step size along the stream- wise direction. Results are showed different values of mass transfer parameter (A) . It was found that the solutions is stable when increases the suction/injection parameter A.